Merge tag 'linear-ranges-lib' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator into regulator-5.8

lib: Add linear ranges helper library and start using it

Series extracts a "linear ranges" helper out of the regulator
framework. Linear ranges helper is intended to help converting
real-world values to register values when conversion is linear. I
suspect this is useful also for power subsystem and possibly for clk.

1 files changed, 48 insertions, 0 deletions

diff --git a/include/linux/linear_range.h b/include/linux/linear_range.h
new file mode 100644
index 000000000000..17b5943727d5
--- /dev/null
+++ b/include/linux/linear_range.h
@@ -0,0 +1,48 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (C) 2020 ROHM Semiconductors */
+
+#ifndef LINEAR_RANGE_H
+#define LINEAR_RANGE_H
+
+#include <linux/types.h>
+
+/**
+ * struct linear_range - table of selector - value pairs
+ *
+ * Define a lookup-table for range of values. Intended to help when looking
+ * for a register value matching certaing physical measure (like voltage).
+ * Usable when increment of one in register always results a constant increment
+ * of the physical measure (like voltage).
+ *
+ * @min:  Lowest value in range
+ * @min_sel: Lowest selector for range
+ * @max_sel: Highest selector for range
+ * @step: Value step size
+ */
+struct linear_range {
+	unsigned int min;
+	unsigned int min_sel;
+	unsigned int max_sel;
+	unsigned int step;
+};
+
+unsigned int linear_range_values_in_range(const struct linear_range *r);
+unsigned int linear_range_values_in_range_array(const struct linear_range *r,
+						int ranges);
+unsigned int linear_range_get_max_value(const struct linear_range *r);
+
+int linear_range_get_value(const struct linear_range *r, unsigned int selector,
+			   unsigned int *val);
+int linear_range_get_value_array(const struct linear_range *r, int ranges,
+				 unsigned int selector, unsigned int *val);
+int linear_range_get_selector_low(const struct linear_range *r,
+				  unsigned int val, unsigned int *selector,
+				  bool *found);
+int linear_range_get_selector_high(const struct linear_range *r,
+				   unsigned int val, unsigned int *selector,
+				   bool *found);
+int linear_range_get_selector_low_array(const struct linear_range *r,
+					int ranges, unsigned int val,
+					unsigned int *selector, bool *found);
+
+#endif